The present invention relates to a color picture tube with a shadow mask.
A shadow mask for a color picture tube has a large number of regularly aligned apertures. The number of electrons passing through the apertures is about 1/3 or less the total number of electrons. The remaining electrons bombard and heat the shadow mask, resulting in thermal expansion of the shadow mask and degradation of color purity.
In a conventional color picture tube with a shadow mask, beam mislanding caused by thermal expansion must be limited. For this reason, improvements in the shadow mask structure itself, the assembly of the shadow mask and its support, and the shadow mask material have all been explored. However, no substantial solutions have been found so far.